Designed for athletes to monitor their internal body temperature, the CorTemp consists of a small pill that you gulp down with some water, and a handheld device that thankfully stays external. The CorTemp data recorder picks up the wireless signal from the pill and keeps track of 99 different sensors simultaneously and stores data for downloading onto your PC to analyze later.

The pill consists of sophisticated instruments and a battery, which probably makes it not so cheap to make. However, we'll be willing to trade a few more bucks to ensure that these pills aren't reusable—Even if CorTemp says it's "designed for human use only." – Jason Chen